An 8-year-old boy from Guatemala died in government custody early Tuesday, U.S. immigration authorities, marking the second death of an immigrant child in detention this month.

U.S. Customs and Border Protection said in a news release that the boy died shortly after midnight Tuesday.

The boy showed "signs of potential illness" Monday and was taken with his father to a hospital in Alamogordo, New Mexico, the agency said. There, he was diagnosed with a cold and a fever, was given prescriptions for amoxicillin and Ibuprofen and released Monday afternoon.

The boy was returned to the hospital Monday evening with nausea and vomiting and died there just hours later, CBP said.

The agency said the cause of the boy's death has not been determined and that it has notified the Department of Homeland Security's inspector general and the Guatemalan government.

A CBP spokesman declined to elaborate Tuesday, but said more details would be released shortly.

A 7-year-old Guatemalan girl died earlier this month after being apprehended by border agents. The body of the girl, Jakelin Caal, was returned to her family's remote village Monday.

The boy's death came on the same day that Jakelin Caal, a Guatemalan migrant girl who died in U.S. custody under similar circumstances earlier this month, was buried.

Her body was repatriated on Sunday and after a long journey reached the remote village where her family lives without electricity and other basic services.

"This girl left home happy searching for a dream, but unfortunately died on the way," community leader Alberto Pop told AFP in the cemetery in the community of Maya Q'eqchi'.

"You hear that in the United States they pay well, not like the companies here in Guatemala -- that's why people leave," said Pop, whose 22-year-old son Joaquin left in November in search of the American dream.

"I don't know if he is alive or dead," Pop said.

"Unfortunately, these decisions (to migrate) are made because of scarce economic resources," Jakelin's cousin Mario Caal said at the funeral.

Jakelin Caal's December 8 death reignited debate in the United States over immigration policy and the treatment of migrants.

President Donald Trump has made hardline immigration policies a central plank of his presidency, drawing fire from critics who accuse him of demonizing migrants for political gain.

He is locked in a battle with Congress over funding for his planned border wall, which he claims will stem migration from Latin American countries plagued by gang violence and poverty.

"Heartbroken to hear of a second child's death in CBP custody," tweeted Nydia Velazquez, a Democratic congresswoman from New York.

"We must demand accountability, find answers and put an end to this Administration's hateful, dangerous anti-immigrant policies."